1. Field of the Invention
The present invention relates to novel pigment preparations based on diketopyrrolopyrrole pigments and basic perylene dispersants, having improved coloristic and rheological properties, and to their preparation and use for pigmenting high molecular mass materials.
2. Description of the Related Art
Pigment preparations are combinations of pigments and pigment dispersants that are structurally analogous to pigments and are substituted by groups having a specific effect. The dispersants are added to the pigments in order to facilitate their dispersion in the application media, especially in varnishes, and in order to improve the rheological and coloristic properties of the pigments. The viscosity of the highly pigmented paint concentrates (millbase) is lowered and the flocculation of the pigment particles reduced. This makes it possible, for example, to enhance the transparency and gloss. Such enhancement is particularly desirable in the case of metallic pigments.
JP-A-03-026 767 discloses basic sulfonamides of diketopyrrolopyrroles and their use as dispersants with various pigments.
DE-A-197 09 798 discloses pigment preparations comprising asymmetric, and U.S. Pat. No. 4,762,569 the production of pigment preparations comprising symmetric, perylene-3,4,9,10-tetracarboxylic diimides. The use of these perylene dispersants with diketopyrrolopyrrole pigments, however, has not been described.
In the case of diketopyrrolopyrrole pigments there was a need for improvement and thus the object was to provide diketopyrrolopyrrole pigment preparations which satisfy the present-day requirements of the state of the art in terms of coloristics, rheology and universal applicability.
It has been found that this object is surprisingly achieved by means of pigment preparations which in addition to the diketopyrrolopyrrole pigment comprise certain symmetric or asymmetric perylene-3,4,9,10-tetracarboxylic diimides. It was unforeseeable that a combination of a diketopyrrolopyrrole pigment with a pigment dispersant that was not a structural derivative of a diketopyrrolopyrrole would exhibit advantages over the diketopyrrolopyrrole pigment alone.
The invention provides pigment preparations comprising
a) at least one diketopyrrolopyrrole pigment or a mixed crystal containing a diketopyrrolopyrrole pigment, and
b) at least one pigment dispersant of the formula (I), 
xe2x80x83in which the two radicals Z are identical or different and have the definition Z3 or Z4 with the proviso that both radicals Z are not simultaneously Z4, and in which
Z3 is a radical of the formula (Ic), 
xe2x80x83in which
R2 and R3 are identical or different and are a hydrogen atom, a substituted or unsubstituted or partly fluorinated or perfluorinated alkyl group having 1 to 20 carbon atoms, or a substituted or unsubstituted or partly fluorinated or perfluorinated alkenyl group having 2 to 20 carbon atoms, possible substituents being hydroxyl, phenyl, cyano, chloro, bromo, C2-C4-acyl and C1-C4-alkoxy and preferably being 1 to 4 in number, or
R2 and R3 together with the nitrogen atom form a saturated, unsaturated or aromatic heterocyclic ring with or without a further nitrogen, oxygen or sulfur atom in the ring; and
X is a branched or unbranched C2-C6-alkylene radical or a C5-C7-cycloalkylene radical which can be substituted by from 1 to 4 C1-C4-alkyl radicals, hydroxyl radicals, hydroxyalkyl radicals having 1 to 4 carbon atoms and/or by 1 or 2 further C5-C7-cycloalkyl radicals;
Z4 is hydrogen, hydroxyl, amino, phenyl, (C1-C4-alkyl)phenyl or C1-C20-alkyl, it being possible for the phenyl ring and the alkyl group to be substituted by one or morexe2x80x94e.g., 1, 2, 3 or 4xe2x80x94substituents from the group consisting of Cl, Br, CN, OH, C6H5, carbamoyl, C2-C4-acyl and C1-C4-alkoxyxe2x80x94e.g., methoxy or ethoxyxe2x80x94and for the phenyl ring to be substituted by NR2R3, R2 and R3 being as defined above, or for the alkyl group to be perfluorinated or partly fluorinated.
Depending on the radicals Z selected, symmetric or asymmetric pigment dispersants of the formula (I) are obtained, asymmetric pigment dispersants of the formula (I) including those having different radicals Z3.
Advantageous pigment dispersants, for example, are those of the formula (I) in which X is a C2-C4-alkylene radical or cyclohexylene.
Advantageous pigment dispersants, for example, are those of the formula (I) in which
R2 and R3 independently of one another are a hydrogen atom, a C1-C6-alkyl group, or a C1-C6-alkyl group substituted by 1 or 2 substituents from the group consisting of hydroxyl, acetyl, methoxy, ethoxy, chloro and bromo, or R2 and R3 together with the adjacent nitrogen atom form an imidazolyl, piperidyl, morpholinyl, pipecolinyl, pyrrolyl, pyrrolidinyl, pyrazolyl or piperazinyl ring.
Particularly advantageous pigment dispersants are, for example, those of the formula (I) in which Z3 has one of the definitions xe2x80x94(CH2)2xe2x80x94NH2, xe2x80x94(CH2)3xe2x80x94NH2, 
xe2x80x94CH2xe2x80x94CH(CH3)xe2x80x94NH2, xe2x80x94CH2xe2x80x94C(CH3)2xe2x80x94CH2xe2x80x94NH2, 
xe2x80x94(CH2)2xe2x80x94NHxe2x80x94CH3, xe2x80x94(CH2)2xe2x80x94N(CH3)2, xe2x80x94(CH2)2xe2x80x94NHxe2x80x94CH2xe2x80x94CH3, xe2x80x94(CH2)2xe2x80x94N(CH2xe2x80x94CH3)2, xe2x80x94(CH2)3xe2x80x94NHxe2x80x94CH3, xe2x80x94(CH2)3xe2x80x94N(CH3)2, xe2x80x94(CH2)3xe2x80x94NHxe2x80x94CH2xe2x80x94CH3 and xe2x80x94(CH2)3xe2x80x94N(CH2xe2x80x94CH3)2.
Advantageous pigment dispersants are, for example, those of the formula (I) in which Z4 is hydrogen, amino, phenyl, benzyl, NR2R3-substituted phenyl or benzyl, C1-C6-alkyl or a C2-C6-alkyl substituted by 1 or 2 substituents from the group consisting of hydroxyl, acetyl, methoxy and ethoxy, and with particular preference hydrogen, 
methyl, ethyl, propyl, butyl, benzyl, hydroxyethyl, hydroxypropyl or methoxypropyl.
The perylene compounds of the formula (I) that are used in accordance with the invention as pigment dispersants as per b) can be prepared, for example, in accordance with DE-A-197 09 798 or in accordance with U.S. Pat. No. 4,762,569.
Component a) comprises diketopyrrolopyrrole pigments, mixtures of at least 2xe2x80x94e.g., 2 or 3xe2x80x94such pigments, or mixtures comprising at least 1xe2x80x94e.g., 1, 2 or 3xe2x80x94diketopyrrolopyrrole pigments, and also mixed crystals containing diketopyrrolopyrrole pigments, which may also be present in the form of conventional pigment preparations.
For the purposes of the present invention, suitable diketopyrrolopyrroles include or are, for example, C.I. Pigment Red 254 (C.I. No. 56 110), C.I. Pigment Red 255 (C.I. No. 56 1050), C.I. Pigment Red 264 (C.I. No. 561 300), C.I. Pigment Red 270, C.I. Pigment Red 272 (C.I. No. 56 1150), C.I. Pigment Orange 71 (C.I. No. 561 200), C.I. Pigment Orange 73 (C.I. No. 561 170). Component a) can also, for example, be a mixture of a diketopyrrolopyrrole and a quinacridone pigment.
The amount of the pigment dispersants of b) of the formula (I) in the pigment preparations of the invention can vary within wide limits provided it does not adversely affect the target pigment quality; in general, however, the amount is from 1 to 40% by weight, preferably from 2 to 30% by weight, based on the overall weight of the pigment preparation.
The pigment preparations of the invention may further include surface-active agents and other conventional additives, such as, for example, fillers, standardizers, resins, defoamers, antidust agents, extenders, shading colorants, preservatives and drying retarders.
Preferred pigment preparations for the purposes of the present invention consist essentially of
i) from 40 to 99% by weight, preferably from 70 to 98% by weight, of component a);
ii) from 1 to 40% by weight, preferably from 2 to 30% by weight, of at least one, preferably 1, 2 or 3, pigment dispersants as per b) of the formula (I);
iii) from 0 to 20% by weight, preferably from 0.1 to 15% by weight, of surface-active agents; and
iv) from 0 to 20% by weight, preferably from 0.1 to 10% by weight, of other, conventional additives,
the fractions of the respective components being based on the overall weight of the preparation (100% by weight).
Suitable surface-active agents include conventional anionic, cationic or nonionic surfactants or mixtures thereof, examples of anionic substances being fatty acid taurides, fatty acid N-methyl taurides, fatty acid isethionates, alkylbenzenesulfonates, alkylnaphthalenesulfonates, alkylphenol polyglycol ether sulfates and fatty alcohol polyglycol ether sulfates; fatty acids, e.g., palmitic, stearic and oleic acids; soaps, e.g., alkali metal salts of fatty acids, naphthenic acids and resin acids, such as abietic acid, alkali-soluble resins, such as rosin-modified maleate resins and condensation products based on cyanuric chloride, taurine, N,N-dialkylaminoalkylamine, such as N,N-diethylaminopropylamine, and p-phenylenediamine; preference is given to resin soaps, i.e., alkali metal salts of resin acids. Examples of suitable cationic substances are quaternary ammonium salts, fatty amine ethoxylates, fatty amine polyglycol ethers, and fatty amines. Examples of suitable nonionic substances are amine oxides, fatty alcohol polyglycol ethers, fatty acid polyglycol esters, and alkylphenol polyglycol ethers.
The pigment preparations of the invention are generally solid systems of free-flowing pulverulent consistency, or granules.
The dispersing effect which can be achieved in accordance with the invention is assumed to derive from a modification of the surface structure of the base pigments by the pigment dispersants of b). Thus in a range of cases the efficacy of the pigment dispersants of b) and the quality of the pigment preparations produced therewith are dependent on the point in time at which the pigment dispersants of b) are added in the production process of the pigment of a). The pigment dispersants of b) can be added simultaneously or at different points in time or can be mixed prior to their addition.
The efficacy of the pigment dispersants of b) may also depend on their particle size and particle morphology and on the extent of the available pigment surface. It may be advantageous to add the pigment dispersants of b) to the pigment of a) only in the prospective application medium. The optimum concentration of the pigment dispersants of b) in each case must be determined by means of preliminary guideline experiments, since the enhancement of the properties of the pigments of a) is not always in linear proportion to the amount of pigment dispersant. The pigment preparations of the invention can be mixtures of one or more, preferably 1 or 2, pigments of a) with one or more, preferably 1 or 2, of the pigment dispersants of b).
The invention also provides a process for producing a pigment preparation of the invention, which comprises mixing the pigment dispersant(s) of b) and the pigment(s) of a) with one another or allowing them to act on one another at any desired point in time during their production process.
The production process of an organic pigment embraces its synthesis, possible fine division, by grinding or reprecipitation, for example, possibly a finish, and its isolation as a presscake or in the form of dry granules or powder. For example, the pigment dispersants of b) can be added prior to or during the pigment synthesis, immediately prior to or during a fine division process or a subsequent finish. The temperatures prevailing in the course of these processes can be, for example, from 0 to 200xc2x0 C. The pigment dispersants of b) can of course also be added in portions at different times.
The addition of the pigment dispersants of b) as part of a fine division process takes place, for example, prior to or during the dry grinding of a crude pigment with or without additional milling auxiliaries on a rollmill or vibratory mill, or prior to or during the wet grinding of a crude pigment in an aqueous, aqueous-organic or organic grinding medium on, for example, a bead mill.
It has also proven suitable to add the pigment dispersants of b) before or after finishing the pigment of a) in an aqueous, aqueous-alkaline, aqueous-organic or organic medium. The pigment dispersants of b) can also be added and incorporated to the water-moist pigment presscake before drying, in which case the pigment dispersants of b) may themselves likewise be present as presscakes. A further possibility is to make dry mixes of powders or granules of the pigment dispersants of b) with the powder or granules of one or more pigments of a).
The pigment preparations obtainable in accordance with the present invention are notable for their outstanding coloristic and Theological properties, especially for outstanding rheology, high flocculation stability, high transparency, ready dispersibility, excellent gloss behavior, high color strength, excellent fastness to overcoating and to solvents, and very good wetfastness, for example. They are suitable for use in both solventborne and aqueous systems.
The pigment preparations produced in accordance with the invention can be used to pigment high molecular mass organic materials of natural or synthetic origin, examples being plastics, resins, varnishes, paints, electrophotographic toners and developers, and writing, drawing and printing inks.
Examples of high molecular mass organic materials which can be pigmented with the pigment preparations are cellulose ethers and cellulose esters, such as ethylcellulose, nitrocellulose, cellulose acetate or cellulose butyrate, natural resins or synthetic resins, such as addition-polymerization resins or condensation resins, e.g., amino resins, especially urea-formaldehyde and melamine-formaldehyde resins, alkyd resins, acrylic resins, phenolic resins, polycarbonates, polyolefins, such as polystyrene, polyvinyl chloride, polyethylene, polypropylene, polyacrylonitrile, polyacrylates, polyamides, polyurethanes or polyesters, rubber, casein, silicone, and silicone resins, individually or in mixtures.
It is unimportant whether the abovementioned high molecular mass organic compounds are present in the form of plastic masses, melts, spinning solutions, varnishes, paints or printing inks. Depending on the intended use it is found advantageous to utilize the pigment preparations of the invention as a blend or in the form of prepared formulations or dispersions. Based on the high molecular mass organic material to be pigmented, the pigment preparations of the invention are used in an amount of preferably from 0.05 to 30% by weight, more preferably from 0.1 to 10% by weight.
The pigment preparations of the invention are also suitable as colorants in electrophotographic toners and developers, such as one- or two-component powder toners (also called one- or two-component developers), magnetic toners, liquid toners, polymerization toners, and specialty toners, for example (L. B. Schein, xe2x80x9cElectrophotography and Development Physicsxe2x80x9d; Springer Series in Electrophysics 14, Springer Verlag, 2nd edition, 1992).
Typical toner binders are addition polymerization, polyaddition and polycondensation resins, such as styrene, styrene-acrylate, styrene-butadiene, acrylate, polyester, and phenol-epoxy resins, polysulfones, polyurethanes, individually or in combination, and also polyethylene and polypropylene, which may include further constituents, such as charge control agents, waxes or flow assistants, or may be modified subsequently with these additives.
Furthermore, the pigment preparations of the invention are suitable as colorants in powders and powder coating materials, especially in triboelectrically or electrokinetically sprayable powder coating materials, which are used to coat the surfaces of articles made, for example, of metal, wood, plastic, glass, ceramic, concrete, textile material, paper or rubber (J. F. Hughes, xe2x80x9cElectrostatics Powder Coatingxe2x80x9d Research Studies, John Wiley and Sons, 1984).
Typical powder coating resins employed are epoxy resins, carboxyl- and hydroxyl-containing polyester resins, polyurethane resins and acrylic resins, together with customary hardeners. Resin combinations are also used. For example, epoxy resins are frequently used in combination with carboxyl- and hydroxyl-containing polyester resins. Typical hardener components (depending on the resin system) are, for example, acid anhydrides, imidazoles and also dicyanodiamide and derivatives thereof, blocked isocyanates, bisacylurethanes, phenolic resins and melamine resins, triglycidyl isocyanurates, oxazolines, and dicarboxylic acids.
In addition, the pigment preparations of the invention are suitable for use as colorants in inkjet inks on either an aqueous or nonaqueous basis and in those inks which operate in accordance with the hot-melt technique.
The pigment preparations of the invention are also suitable, however, as colorants for color filters and for both additive and subtractive color generation.
It is also possible for the pigment dispersants of b) to be added to the pigment dispersant of a), or vice versa, only in the application medium. The invention therefore also provides a prepared pigment formulation consisting essentially of said pigment of a), of said pigment dispersants of b), of said high molecular mass organic material, especially varnish, and, if desired, surface-active agents and/or other customary additives. The overall amount of pigment of a) plus pigment dispersants of b) is judiciously from 0.05 to 30% by weight, preferably from 0.1 to 10% by weight, based on the overall weight of the prepared pigment formulation.
In order to evaluate the properties in the coatings sector of the pigment preparations produced in accordance with the invention, a selection was made, from among the large number of known varnishes, of an alkyd-melamine resin varnish (AM) containing aromatic components and based on a medium-oil alkyd resin and on a butanol-etherified melamine resin, of a polyester varnish (PE) based on cellulose acetobutyrate and on a melamine resin, of a high-solid acrylic resin stoving varnish based on a nonaqueous dispersion (HS), and of a polyurethane-based aqueous varnish (PU).
The color strength and shades were determined in accordance with DIN 55986. The rheology of the millbase after dispersion (millbase rheology) was evaluated visually on the basis of the following five-point scale:
Following dilution of the millbase to the final pigment concentration, the viscosity was evaluated using the Rossmann viscospatula type 301 from Erichsen. Gloss measurements were carried out on cast films at an angle of 20xc2x0 in accordance with DIN 67530 (ASTM D 523) using the xe2x80x9cmultiglossxe2x80x9d gloss meter from Byk-Mallinckrodt. The solvent fastness was determined in accordance with DIN 55976. The fastness to overcoating was determined in accordance with DIN 53221.